Method of preventing the destruction of coke-oven walls through the alkalies contained in the charge.



V UNITED STATES PA-TENT OFFICE.

HEINRICH KOPPERS, OF ESSEN-ON-THE -RUHR, GERMANY.

METHOD OF PREVENTING THE DESTRUCTION OF COKE-OVEN WALLS THROUGH THE ALKALIES CONTAINED IN THE CHARGE.

i No Drawing.

. render the said alkalies harmless to the oven for making the Walls are 3 Serial No. 481,569.

To all whom it may concern:

Be it known that I, HEINRICH Korrnns, a subjectof the German Emperor, residing at Essen-on-the Ruhr, in Germany, have invented a certain new and useful Preventing the Destruction of Coke-Oven Walls Through the Alkalies Contained in the Charge, of which the following is a I specification.

It is .Well known that the treatment of certain kinds of coal in coke-ovens is highly destructive to the Walls of the ovens, more particularly at high temperatures. It has been found that the damaged walls and the pieces broken therefrom always contain a considerable quantity of easily fusible alkaline silicates, the presence of which has caused the bricks to become warped and to shrink and crack. The presence of these silicates is due to alkalies which are introduced with the charge and act on the silica contained in the walls. If the bricks used rich in silica, and not presse scales and patches become detached therefrom; mina become distorted. The alkalies referred to are soluble and insoluble salts, of which only small traces can be detected in the water dripping from the coal; this indicates that the said alkalies are intimately mixed with the coal. y

The object of thepresent invention. is to walls. The alkalies chlorids, are

present in the charge, usually decomposed by the heat, the

acid (usually hydrochloric acid) being separated, :and iydrates being formed with the water which is present, in the form of vapor, '40

The acid forming so-called and the amount of fixed quently ascertainable may be even at the hi her temperatures. reacts with the ammonia, fixed ammonia, ammonia subse taken as an indication of the amount of alkali introduced with the charge. In apparent contradiction to this view is the fact explained by the fact that the ash that the coking of certain k nds of coal is not accompanied by destruction of the ovenwalls, though it results in the production of a large quantity of fixed ammonia. This. is of such coal is rich in silica, withwhich the hydrates immediately react, so that the distilling or sublimation of the said hydrates is prevented.

Method of pressed bricks rich in alu-' silica in the oven-walls, inasmuch as the tendency of the hydrates to react with silica is directly and immediately satisfied by the added silica.

The silica is preferably added in the form of sand, as being the simplest and cheapest form available.

Of the alkalies, earth alkalies and oxide of heavy metals resent in the coal, and ascertainable in the ash, only the alkalies which are volatilized at red-heat, and flow with the as from the center of the charge to the walls, are liable to injure the latter; the added silica serves more particularly for binding these alkalies. The amount of al kali which passes to the walls with the moisture is comparatively small, inasmuch as only the coal in direct contact with the walls gives off moisture to the latter. Most of the alkali remains in the charge, in the form of hydrate, until at therequisite temperature sublimation occurs and the hydrate is bound with theexcess of silica.

The quantity of ashes of coking coal averages about 68 per cent,and contains s1 l1- cates, the composition of WhlCh varies greatly with the nature of the coal. Some ashes are basic, while others are acid. The following-table gives the analysis of the ashes of a coking coal, showing also the amount of silica necessary for binding the bases:

A120, 24.83% requires for binding "22.00% so,

3 a K (6 H a (l Feo, 26.9 09.0 6.71% 3.60% u n H I K 0 4.80% "f 1,54% SiO 35.42% 43.31% Present in the coal. 35.42%

Necessary to be added.. 7.89

If the coal contains 6% are thus to be added to said coal. But in order to insure a combinationof all the bases with the silica, a slight excess of the latter should be used. Thus,-about 12% of sand are added to the coal which should be thorou hly intermingled therewith;

hat I claim as my invention and desire Patented Jan. 4, 1910,,

ashes, 0.47% SiO intermixing the coal and the added si to secure by Letters Patent of the United States is Method of preventing the destruction of coke oven walls through the alkalies contained in the charge, which consists in adding to the coal a quantity of silica sufiicient to bind the excess of alkalies contained in the coal and which remains uncombined by reason of the insuflicient quantity of silica naturally carried by the coal, thoroughly ice, 1

and coking the mixture in a coking chamber having silicious walls, thesilica to the coal preventing the. extraction of the silica from said walls.

In'witness whereof I have, signed this specificationin the presence of two witnesses.

Witnesses:

R. GUNDERSON, JOHN H. GARNSEY.

the addition of HEINRICH KOPPERS. l 

